V G wrote:
> A question: Since the data lines have to be set at a certain voltage
> (with resistor voltage dividers), and the battery pack voltage will
> vary between
> 4.4 - 5.6 volts, how would I get a steady voltage on the data lines
> to tell the iPhone to draw 1 Amp? Would I need to just stick a low
> power voltage regulator at around 3.0 or 3.3 volts and create a
> divider from there?

That's one way to do it if the voltage values are absolute.  There is a off
chance the voltage values are ratiometric to the charging voltage, in which
case all you need are resistors.  Normal USB signalling levels are 0-3.3V
regardless of the USB power voltage, but what Apple is doing is outside the
USB spec so you have to guess.  The voltages could be absolute, or they
could be ratiometric.  Probably absolute, but that's just a guess.

--=20
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